Radiofrequency transformer



Sept. 14, 1926. 1,599,531

H. w. HOUCK IADIOIREQUENCY TRANSFORIER F1101! Feb. 12. 1924 INVEN TOR.

5922) I44 HOUCK 42. ATTORNEY.

Patented Sept. 14, 1926.

iUNlTED STATES PATENT OFFICE.

man w. nopcx, or E481 ORANGE, NEW massif, assronoa TO nunnimn connENsER AND RADIO CORPORATION, a CORPORATION OF DELAWARE mmornnounncv 'rnansronuan.

Application filed Tebruary 12, 1924. Serial No. 892,310.

My invention relates to improvements in transformers,- especially transformers for purposes of communicatlon by lfldlO.

An object of the invention is to provide a transformer capable of operating at radio frequency in amplification circuits, and of.

simple design and inexpensive construction; so that it can easily be made in large quantities and at minimum expense. Another object of the invention is to provide a transformer that will operate with high efficiency and in a satisfactory manner over a relatively wide range or band of fre-. quencies and wave lengths, (or over a narrow range if desired); and that will be of sufficiently low distributed capacity to enable the secondary thereof to deliver a voltage suitable for amplification to the required degree. v

A further object of, the invention is to provide a transformer which will give voltage amplification that is nearly constant, when a wide range of wave lengths is'contemplated, for all frequencies or wave lengths within its field of use, with the re-' sult that interference usually encountered in multistage amplification, due to oscillation in different parts of the apparatus; is eliminated.

Other objects and advantages will appear from the following specification, taken with the accompanying drawings, and the novel features of the invention are defined in the appended claims. But I do not wish to be restricted to the exact structural details disclosed herein; as I may vary the size, shape and arrangement of parts, within the scope and spirit. of the invention, as indicated by the broad meanings of the terms in which the claims are expressed.

On the drawings,

Figure 1 is a side view of a transformer according to my invention;

Figure 2 is a similar view partly in section; I

Figure 3 an end view thereof; and Figure 4 shows a modified arrangement of the windings.

The same numerals identify the same parts throughout.

' In practice, the form of a tube or spool 1, of Wood or other material having a plurality of exterior circumferential grooves 2 for the primary winding, and a plurality of similar grooves I employ a hollow support in 3 for the secondary winding. The grooves,

2 and 3 are adjacent opposite extremities of the 'spool, and the turns. of a the primary winding in the grooves 2 are indicated at 4,

in sections,the number of sections being equal to the number of grooves, though in 1 some instances the primary and secondary may each consist of a single winding and separate sections be dispensed with. The sections of the primary are in series; likewise the sections of the secondary 5.

By thus winding the primary and secondary coils in sections, the distributed capacity of the coils of the transformer, is much reduced and distributed, and the selfinduction made relatively greater. Hence the voltage that can be obtained from the terminals of the secondary can be much increased, for any given value of current flowing through the primary coils.

The support 1 has an axial bore 6, in

which is a magnetic core 7. This core is line with each other, with their inner ends at the middle of the spool, where they are separated by a gap in which is disposed a dlsk of paper cardboard,.or fibre 8; and the outer ends of the core project from the opposite extremities of the spool. The two halves fit into the bore 6 tightly, and the piece of fibre 8, when the sections are forced into the spool till they both abut this fibre at their inner ends, will insure a gap of constant length. The dimensions of this gap are selected according to the size of the core and of the windings, and its presence enables the transformer to attain high efliciency for all frequencies or wave lengths with which it will operate.

From the foregoing description, it will be clear that I have invented a novel and valuable device of superior mode of operation, and great efiiciency, and at the same time,

, the transformer is quite simple in construction, includes only a few parts, and is very easy and inexpensive to make.

My transformer can be designed to operate over a wide band of wave lengths and a graph plotted to show the relations between voltage amplification and wave lengths will be without peaks, and willshow only small variations of voltage amplification over its range. Therefore. in practice the interference that would otherwise result. from oscillations in the parts of the apparatus is avoided. I can also design the transformer to operate only for selected wave lengths in a narrow range if desired.

Preferably the spool 1 is of wood or some, other inaterial suitable for a transformer in which low distributed capacity is sought.

The core T is in bar form, with an air path for the lines of force between its outer ends. and the small air gap between its inner ends. A magnetic circuitconsisting in large part of an air path with the remainder of the path of metal. greatly facilitates the proper operation of a transformer of this class.

Under some circumstances, I may make the core 7 of non-magnetic metal, as the use of iron or other metal that is magnetic may not always be essential.

In some cases the windings can be ar ranged as illustrated in Figure 4. Here one of the sections of the primary winding 4 is in the groove 2 at one end of the spool and one section of the secondary 5 is in the groove 3 at the opposite end. other section of the secondary 5 is placed in the other groove 2 and the remaining section of the primary 4 in the other groove 3. Thus each section of the secondary 5 lies between the two sections of primary 4 and vice Then the versa: and the sections of the primary and secondary are in alternation.

Figure 4 shows the spool and the core in broken lines only as this view is primarily intended to present the special arrangement of coils described.

.IIaving described my invention, what I believe to be new and desire to secure and protect by Letters Patent of the United States i$:

l. The combination of a hollow insulating support open at both ends, a magnetic core in the support. said core comprising sections one of which projects into each open end of the support. the adjacent extremities of said sections in the support being spaced apart. and primary and secondary windings carried by the support.

9. A transt'orn'ier comprising a hollow insulating support having peripheral grooves in its surtace .a primary and a secondary winding carried by the support, each winding comprising sections disposed in said grooves. and a magnetic core in the support, the core including sections. the support being open at both ends and'one of the sections projecting into each open end of the support. the adjacent inner extremities of said sections being spaced apart in said support.

In testimony whereof I atlix my signature.

HARRY IV. IIOUCK. 

